The Dutch port of Rotterdam has seized 90,000 bottles of Russian vodka allegedly destined for North Korean leader Kim Jong-un and his top generals. Customs officers nabbed the 3,000 cases of vodka on Friday in a vessel belonging to the Chinese company Cosco Shipping on a tip from the Russian foreign ministry. They believe the intended recipient was Kim and military commanders. The confiscation was followed by findings that a Russian tanker secretly transferred fuel to a North Korean ship at sea at least four times in 2017 and 2018, which would violate international sanctions over Pyongyang's nuclear missile programme. Two crew members told Reuters that the ship left Vladivostok ostensibly for China, but instead met up with the North Korean tanker Chon Moyng-1 at night while it was not transmitting its position. The meeting between Donald Trump and Kim Jong-un in Singapore in June, which has produced few concrete results Credit: Evan Vucci/AP News of these attempts to skirt the sanctions came ahead of a summit in Vietnam's capital Hanoi on Wednesday between Kim and Donald Trump, the US president. The Russian foreign minister said during his own visit to Hanoi on Monday that the US had asked Russia's advice on how to approach the summit. Moscow has recommended Washington offer security guarantees to Pyongyang in exchange for disarmament steps. The United Nations has capped petroleum exports to North Korea and banned luxury good exports entirely, but Kim frequently tries to circumvent these measures. Last year, the UN listed the Chon Moyng-1 as having disobeyed sanctions with ship-to-ship fuel transfers. Previous seizures have included champagne, cheese and televisions bound for North Korea. The vodka cases found on Friday were hidden under an aircraft fuselage. Kim Jong-un visits the North Korean embassy in Vietnam before his expected meeting with Donald Trump this week Credit: The Asahi Shimbun via Getty The UN estimates that 11 million North Koreans, nearly half the country's population, are affected by chronic food insecurity and access to basic life-saving services such as health care, water and sanitation. Around a fifth of all children in North Korea are malnourished, according to the UN. The meeting with Kim in Hanoi is intended to discuss US-Korean relations but is not expected to produce any breakthroughs in convincing Pyongyang to end its nuclear weapons programme. There are hopes that North Korea will renew its pledge to suspend nuclear tests and missile firings. The summit follows a historic meeting between Mr Trump and the North Korean leader in Singapore in June last year. While the event was hailed as a triumph for Mr Trump's foreign policy it produced few meaningful concessions from Kim while allowing the dictator to burnish his international standing. US Secretary of State Mike Pompeo will join the summit.